1. Field of the Invention
The present invention relates to a silicon structure, a method for manufacturing the silicon structure, and a method for manufacturing a capacitor including the silicon structure.
2. Description of the Related Art
In recent years, accuracy of microfabrication technique has been improving steadily, a nano-meter scale structure (a nano-structure) and nano-technology for manufacturing the nano-structure have attracted attention in a variety of electronics fields. As a method for manufacturing the nano-structure, a method in which a pattern is directly formed with a lithography technique using light or an electron beam is often used.
As a contrasting method, there is a method utilizing a phenomenon in which an ordered pattern is formed spontaneously to form a nano-structure without using an artificial technique such as a lithography technique. Since a nano-structure is formed by utilizing such a phenomenon, a pattern does not need to be formed directly, so that nano-structures can be formed simply and easily in a large area.
As an example of a nano-structure, there is hemispherical-grain-silicon (HSG-Si) (for example, Patent Document 1). The HSG-Si is a hemispherical polysilicon grain. In Patent Document 1, the HSG-Si is formed on an electrode surface of a capacitor to increase a surface area of the electrode and thus storage capacitance is increased.